Apparatus for cutting liquid crystal display panel

ABSTRACT

An apparatus for cutting liquid crystal display panels is disclosed in the present invention. The apparatus includes at least one table receiving bonded mother substrates having a plurality of unit liquid crystal display panels, at least one cutting wheel forming a scribing line on a surface of the bonded mother substrates, and a suction unit coupled to the at least one cutting wheel and sucking in glass debris on the surface of the bonded mother substrates.

[0001] This application claims the benefit of the Korean Application No.P2002-064677 filed on Oct. 22, 2002, which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a liquid crystal display panel,and more particularly, to an apparatus for cutting a liquid crystaldisplay panel to separate a plurality of unit liquid crystal displaypanels from a mother substrate.

[0004] 2. Discussion of the Related Art

[0005] Generally, a liquid crystal display device provides liquidcrystal cells arranged in a matrix form with corresponding data signalsaccording to image information in order to display a desired image bycontrolling light-transmittance of each liquid crystal cell.

[0006] Accordingly, the liquid crystal display device is provided with aliquid crystal display panel where a plurality of liquid crystal cellsof a unit pixel are arranged in a matrix form, and a driver integratedcircuit for driving the liquid crystal cells of the liquid crystaldisplay panel.

[0007] The liquid crystal display panel is composed of a color filtersubstrate and a thin film transistor array substrate attached to face toeach other, and a liquid crystal layer filled between the twosubstrates.

[0008] On the thin film transistor array substrate of the liquid crystaldisplay panel, a plurality of data lines for transmitting data signalssupplied from a data driver integrated circuit to the liquid crystalcells are perpendicular to a plurality of gate lines for transmittingscan signals supplied from a gate driver integrated circuit to theliquid crystal cells. Herein, the liquid crystal cells are arranged ateach intersection of the data lines and the gate lines.

[0009] The gate driver integrated circuit sequentially supplies the scansignals to the plurality of gate lines so that the liquid crystal cellsarranged in a matrix form can be sequentially selected line by line.Also, the data signals are supplied to the liquid crystal cells of theselected one line from the data driver integrated circuit through aplurality of data lines.

[0010] In the meantime, a common electrode and a pixel electrode arerespectively formed at the inner sides of the color filter substrate andthe thin film transistor array substrate facing into each other, therebyapplying an electric field to the liquid crystal layer. At this time, asopposed to the pixel electrode, which is formed correspondingly to eachliquid crystal cell formed on the thin film transistor array substrate,the common electrode is integrally formed on the entire surface of thecolor filter substrate. Accordingly, light-transmittance of the liquidcrystal cells can be individually controlled by controlling a voltageapplied to the pixel electrode when a voltage is applied to the commonelectrode.

[0011] Similarly, a thin film transistor used as a switching device isformed at the respective liquid crystal cells in order to control thevoltage applied to the pixel electrode formed on each liquid crystalcell.

[0012] Meanwhile, the thin film transistor array substrates are formedon a large mother substrate and the color filter substrates are formedon another mother substrate. The two mother substrates are then bonded,so that a plurality of liquid crystal display panels are formed at thesame time to improve yield. Herein, a process for cutting the bondedsubstrates into unit liquid crystal display panels is required.

[0013] Generally, the cutting process of the unit liquid crystal displaypanels includes forming a scribing line at a surface of the mothersubstrate by a diamond wheel having a hardness greater than that ofglass, and breaking the substrate by applying a mechanical forcethereto. Hereinafter, a typical liquid crystal display panel will beexplained with reference to the accompanied drawings.

[0014]FIG. 1 is a schematic view showing a related art unit liquidcrystal display panel prepared by bonding a thin film transistor arraysubstrate and a color filter substrate of the liquid crystal displaydevice.

[0015] As shown in FIG. 1, a liquid crystal display panel 10 includes animage display unit 13 having liquid crystal cells arranged in a matrixform, a gate pad unit 14 connected to gate lines of the image displayunit 13, and a data pad unit 15 connected to data lines. At this time,the gate pad unit 14 and the data pad unit 15 are formed on the endportions of a thin film transistor array substrate 1 which does notoverlap with a color filter substrate 2. The gate pad unit 14 provides ascan signal supplied from a gate driver integrated circuit to the gatelines of the image display unit 13, and the data pad unit 15 providesimage information supplied from a data driver integrated circuit to thedata lines of the image display unit 13.

[0016] On the thin film transistor array substrate 1 of the imagedisplay unit 13, the data lines are arranged to be perpendicular to thegate lines. Then, thin film transistors are formed at each intersectionto switch the liquid crystal cells. Pixel electrodes are connected tothe thin film transistors to drive the liquid crystal cells. Apassivation layer is formed on the entire surface of the thin filmtransistor array substrate 1 to protect the electrodes and the thin filmtransistors.

[0017] Also, the color filters separated by a black matrix for each cellarea are formed on the color filter substrate 2 of the pixel displayunit 13. Additionally, a transparent common electrode as a counterelectrode of the pixel electrode is formed on the color filter substrate2.

[0018] A cell gap is provided between the thin film transistor arraysubstrate 1 and the color filter substrate 2, which are bonded to eachother by a sealant (not shown) formed at the periphery of the imagedisplay unit 13, so as to be spaced apart from each other. A liquidcrystal layer (not shown) is formed in the space between the thin filmtransistor array substrate 1 and the color filter substrate 2.

[0019]FIG. 2 is a cross-sectional view showing a first mother substratehaving thin film transistor array substrates 1 and a second mothersubstrate having color filter substrates 2, wherein the first and secondmother substrates are bonded to each other to form a plurality of liquidcrystal display panels.

[0020] As shown in FIG. 2, each unit liquid crystal display panel hasthe end portions of the thin film transistor array substrate 1protruding longer than the color filter substrate 2. This is because thegate pad unit 14 and the data pad unit 15 are formed at the end portionsof the thin film transistor array substrate 1 which does not overlapwith the color filter substrate 2.

[0021] Hence, the second mother substrate 30 and the color filtersubstrates 2 formed thereon are spaced apart from each other by a dummyregion 31 corresponding to the protruding area of each thin filmtransistor array substrate 1 on the first mother substrate 20.

[0022] Moreover, the unit liquid crystal display panels are arranged soas to maximize the use of the first and second mother substrates 20 and30. Although it may vary depending on the model, the unit liquid crystaldisplay panels are generally spaced apart from each other at a distancecorresponding to a second dummy region 32.

[0023] After the first mother substrate 20 having the thin filmtransistor array substrates 1 is bonded to the second mother substrate30 having the color filter substrates 2, a scribing process and abreaking process are carried out to individually cut each of the liquidcrystal display panels. In this case, the first dummy region 31 formedbetween each color filter substrate 2 of the second mother substrate 30and the second dummy region 32 formed between each unit liquid crystaldisplay panel are removed at the same time.

[0024] The related art cutting process of the unit liquid crystaldisplay panels will be explained with reference to FIGS. 3A to 3J.

[0025] As shown in FIG. 3A, the first mother substrate 20 and the secondmother substrate 30 bonded to each other are loaded on a first table 33.

[0026] Then, as shown in FIG. 3B, the first table 33 moves in onedirection to a previously set distance to sequentially form a firstscribing line 42 on the first mother substrate 20 through a cuttingwheel 41.

[0027] Then, as shown in FIG. 3C, the first and second mother substrates20 and 30 are turned by about 90°. The first table 33 moves back to itsinitial location at the previously set distance to sequentially form asecond scribing line 43 on a surface of the first mother substrate 20through the cutting wheel 41.

[0028] The cutting wheel 41 is bonded to the surface of the first mothersubstrate 20 with a constant pressure to be rotated, thereby forming thefirst and second scribing lines 42 and 43 having a groove on the surfaceof the first mother substrate 20.

[0029] Then, as shown in FIG. 3D, the first and second mother substrates20 and 30 are overturned and are loaded on a second table 34. The secondtable 34 moves in one direction at a previously set distance, andpropagates a crack on the first mother substrate 20 along the secondscribing line 43 by pressing the second mother substrate 30 with abreaking rod 44.

[0030] As shown in FIG. 3E, after the second and first mother substrates30 and 20 are turned by about 90°, the second table 34 moves back to itsinitial location at the previously set distance, and propagates a crackon the first mother substrate 20 along the first scribing line 42 bypressing the second mother substrate 30 with the breaking rod 44.

[0031] As shown in FIG. 3F, after the second and first mother substrates30 and 20 are loaded on a third table 35, the third table 35 moves inone direction at a previously set distance to sequentially form a thirdscribing line 46 on the surface of the second mother substrate 30through a cutting wheel 45.

[0032] As shown in FIG. 3G, the second and first mother substrates 30and 20 are turned by about 90°, and the third table 35 moves back to theinitial location at the previously set distance to sequentially form afourth scribing line 47 on the surface of the second mother substrate 30through the cutting wheel 45.

[0033] The cutting wheel 45 is bonded to the surface of the secondmother substrate 30 with a constant pressure to be rotated, therebyforming the third and fourth scribing lines 46 and 47 having a groove onthe surface of the second mother substrate 30.

[0034] As shown in FIG. 3H, the second and first mother substrates 30and 20 are overturned to be loaded on a fourth table 36. The fourthtable 36 moves in one direction at a previously set distance andpropagates a crack on the second mother substrate 30 along the fourthscribing line 47 by pressing the first mother substrate 20 with abreaking rod 48.

[0035] As shown in FIG. 3I, after the first and second mother substrates20 and 30 are turned by about 90°, the fourth table 36 moves back to theinitial location at the previously set distance and propagates a crackon the second mother substrate 30 along the third scribing line 46 bypressing the first mother substrate 20 with the breaking rod 48.

[0036] As shown in FIG. 3J, the first and second mother substrates 20and 30 are cut into unit liquid crystal display panels as the cracks arepropagated along the first to fourth scribing lines 42, 43, 46, and 47on the first and second mother substrates 20 and 30. The unit liquidcrystal display panels are selectively unloaded using a suction plate 49to be transferred to equipment for a later process.

[0037] In the related art apparatus for cutting liquid crystal displaypanels, when the scribing lines having a groove are formed on thesurface of the substrate by bonding the cutting wheel to the surface ofthe substrate with a constant pressure and turning, glass debris aregenerated from a friction between the cutting wheel and the substrate.

[0038] When the glass debris are adhered to the surface of the substrateor the table on which the substrate is loaded, it causes a scratch orstain thereon.

[0039] The scratch or stain generated on the surface of the substratedeteriorates a picture quality of the liquid crystal display device,thereby increasing the defective proportions of a product and loweringproductivity.

SUMMARY OF THE INVENTION

[0040] Accordingly, the present invention is directed to an apparatusfor cutting a liquid crystal display panel that substantially obviatesone or more of problems due to limitations and disadvantages of therelated art.

[0041] Another object of the present invention is to provide anapparatus for cutting liquid crystal display panels, which prevents theglass debris generated by the friction between a cutting wheel and asubstrate from being adhered to the surface of the substrate or a tableon which the substrate is loaded.

[0042] Additional features and advantages of the invention will be setforth in the description which follows and in part will be apparent fromthe description, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

[0043] To achieve these and other advantages and in accordance with thepurpose of the present invention, as embodied and broadly described, anapparatus for cutting liquid crystal display panels includes at leastone table receiving bonded mother substrates having a plurality of unitliquid crystal display panels, at least one cutting wheel forming ascribing line on a surface of the bonded mother substrates, and asuction unit coupled to the at least one cutting wheel and sucking inglass debris on the surface of the bonded mother substrates.

[0044] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory and are intended to provide further explanation of theinvention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiments of theinvention and together with the description serve to explain theprinciple of the invention.

[0046] In the drawings:

[0047]FIG. 1 is a schematic plane view showing a related art unit liquidcrystal display panel prepared by bonding a thin film transistor arraysubstrate and a color filter substrate to each other;

[0048]FIG. 2 is a cross-sectional view showing a first mother substratehaving thin film transistor array substrates and a second mothersubstrate having color filter substrates according to the related art;

[0049]FIGS. 3A to 3J are perspective views sequentially showing aprocess for cutting unit liquid crystal display panels according to therelated art;

[0050]FIG. 4 is a schematic view showing an apparatus for cutting liquidcrystal display panels according to a first embodiment of the presentinvention;

[0051]FIGS. 5A to 5J are perspective views sequentially showing aprocess for cutting liquid crystal display panels using the apparatusfor cutting liquid crystal display panels according to the firstembodiment of the present invention;

[0052]FIG. 6 is a schematic view showing an apparatus for cutting liquidcrystal display panels according to a second embodiment of the presentinvention;

[0053]FIGS. 7A to 7F are perspective views sequentially showing aprocess for cutting the liquid crystal display panels using theapparatus for cutting liquid crystal display panels according to thesecond embodiment of the present invention;

[0054]FIG. 8 is a schematic view showing an apparatus for cutting liquidcrystal display panels according to a third embodiment of the presentinvention;

[0055]FIGS. 9A to 9F are perspective views sequentially showing aprocess for cutting liquid crystal display panels by using the apparatusfor cutting liquid crystal display panels according to the thirdembodiment of the present invention;

[0056]FIGS. 10A and 10B are schematic views showing another example of asuction hole used in the third embodiment of the present invention;

[0057]FIGS. 11A and 11B are perspective views showing a process forcutting liquid crystal display panels with the second or thirdembodiments of the present invention in more detail; and

[0058]FIG. 12 is a schematic view showing an apparatus for cuttingliquid crystal display panels according to a fourth embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0059] Reference will now be made in detail to the illustratedembodiments of the present invention, examples of which are illustratedin the accompanying drawings. Wherever possible, the same referencenumbers will be used throughout the drawings to refer to the same orlike parts.

[0060]FIG. 4 is a schematic view showing an apparatus for cutting liquidcrystal display panels according to a first embodiment of the presentinvention. As shown in FIG. 4, the apparatus for cutting liquid crystaldisplay panels according to the first embodiment of the presentinvention includes a table 103 on which a first mother substrate 101 anda second mother substrate 102 are loaded, a cutting wheel 105 forforming a scribing line 104 on the surfaces of the first and secondmother substrates 101 and 102, and a suction unit 106 provided at thecutting wheel 105 for sucking in glass debris generated from a frictionbetween the cutting wheel 105 and the first mother substrate 101 orbetween the cutting wheel 105 and the second mother substrate 102.

[0061] In the apparatus for cutting liquid crystal display panelsaccording to the first embodiment of the present invention, the cuttingwheel 105 is rolled onto the surface of the first mother substrate 101or the second mother substrate 102 with a constant pressure, therebyforming the scribing line 104 such as a groove on the surface of thefirst mother substrate or the second mother substrate 102. The suctionunit 106 is connected with the cutting wheel 105, and the cutting wheel105 sucks in glass debris generated on the surface of the first mothersubstrate 101 or the second mother substrate 102. The glass debris aregenerated from the friction between the cutting wheel 105 and the firstmother substrate 101 or the second mother substrate 102.

[0062] Processes for cutting liquid crystal display panels by using thefirst embodiment of the present invention will be explained withreference to FIGS. 5A to 5J.

[0063] First, as shown in FIG. 5A, the first mother substrate 120 andthe second mother substrate 130 are loaded on the first table 133.

[0064] The attached first and second mother substrates 120 and 130 areused to form the thin film transistor array substrate and the colorfilter substrate formed of glass.

[0065] On the thin film transistor array substrate, the data lineshaving image information applied thereto are arranged to perpendicularlycross the gate lines having scan signals applied thereto. Then, thinfilm transistors are formed at each intersection to switch liquidcrystal cells. Pixel electrodes are connected to the thin filmtransistors to drive the liquid crystal cells. A passivation layer isformed on the entire surface of the thin film transistor array substrateto protect the electrodes and the thin film transistors.

[0066] Also, on the color filter substrate, color filters separated by ablack matrix for each cell area are formed. Additionally, a transparentcommon electrode as a counter electrode of the pixel electrode is formedon the color filter substrate.

[0067] As shown in FIG. 5B, the first table 133 moves in one direction,and a cutting wheel 141 is rolled onto the surface of the first mothersubstrate 120 with a constant pressure, thereby sequentially forming afirst scribing line 142 on the first mother substrate 120. At this time,a suction unit 150 is connected with the cutting wheel 141 to suck inthe glass debris generated on the surface of the first mother substrate120 by the friction between the cutting wheel 141 and the first mothersubstrate 120.

[0068] As shown in FIG. 5C, the first and second mother substrates 120and 130 are turned by about 90° and the first table 133 moves back tothe initial location. Subsequently, the cutting wheel 141 is rolled ontothe surface of the first mother substrate 120 with applying a constantpressure, thereby sequentially forming a second scribing line 143 on thesurface of the first mother substrate 120. At this point, the suctionunit 150 is connected with the cutting wheel 141 to suck in the glassdebris generated on the surface of the first mother substrate 120 by thefriction between the cutting wheel 141 and the first mother substrate120.

[0069] As shown in FIG. 5D, the first and second mother substrates 120and 130 are overturned to be loaded on a second table 134. Subsequently,the second table 134 moves in one direction, and propagates a crack inthe first mother substrate 120 along the second scribing line 143 bypressing the second mother substrate 130 with a breaking rod 144.

[0070] As shown in FIG. 5E, the second and first mother substrates 130and 120 are turned by about 90°. The second table 134 moves back to theinitial location, and propagates a crack on the first mother substrate120 along the first scribing line 142 by pressing the second mothersubstrate 130 with the breaking rod 144.

[0071] As shown in FIG. 5F, the second and first mother substrates 130and 120 are loaded on a third table 135, and the third table 135 movesin one direction. A cutting wheel 145 is rolled onto the surface of thesecond mother substrate 130 with applying a constant pressure, therebysequentially forming a third scribing line 146 on the surface of thesecond mother substrate 130. At this point, the suction unit 151 isconnected with the cutting wheel 145 to suck in the glass debrisgenerated on the surface of the second mother substrate 130 by thefriction between the cutting wheel 145 and the second mother substrate130.

[0072] As shown in FIG. 5G, the second and first mother substrates 130and 120 are turned by about 90° and the third table 135 moves back tothe initial location. The cutting wheel 145 is rolled onto the surfaceof the second mother substrate 130 with applying a constant pressure,thereby sequentially forming a fourth scribing line 147 on the surfaceof the second mother substrate 130. At this time, the suction unit 151is connected with the cutting wheel 145 to suck in the glass debrisgenerated on the surface of the second mother substrate 130 by thefriction between the cutting wheel 145 and the second mother substrate130.

[0073] As shown in FIG. 5H, the second and first mother substrates 130and 120 are overturned to be loaded on a fourth table 136. Subsequently,the fourth table 136 moves in one direction, and propagates a crack onthe second mother substrate 130 along the fourth scribing line 147 bypressing the first mother substrate 120 with a breaking rod 148.

[0074] As shown in FIG. 5I, the first and second mother substrates 120and 130 are turned by about 90°. The fourth table 136 moves back to theinitial location, and propagates a crack on the second mother substrate130 along the third scribing line 146 by sing the first mother substrate120 with the breaking rod 148.

[0075] As shown in FIG. 5J, the first and second mother substrates 120and 130 are cut into a plurality of unit liquid crystal display panelsas the cracks are propagated along the first to fourth scribing lines142, 143, 146, and 147 on the first and second mother substrates 120 and130. The unit liquid crystal display panels are selectively unloaded byusing a suction plate 149 for transferring each unit liquid crystaldisplay panel to equipment for a later process.

[0076] In the apparatus and method for cutting liquid crystal displaypanels according to the first embodiment of the present invention, thefirst and second mother substrates are turned four times and overturnedtwice, thereby performing the scribing process four times and thebreaking process four times.

[0077] Accordingly, two scribing equipments each including a turningunit and two breaking equipments each including a turning unit and anoverturning unit are required. This occupies many areas in a workingfield, thereby causing a waste in the installation cost of the equipmentand in the installation space.

[0078] Moreover, too much time is taken to the scribing and breakingprocesses, which eventually decreases productivity.

[0079] Accordingly, upon consideration of such problems, the apparatusfor cutting liquid crystal display panels according to the secondembodiment of the present invention is illustrated in FIG. 6.

[0080] As shown in FIG. 6, the apparatus for cutting liquid crystaldisplay panels according to the second embodiment of the presentinvention includes first and second tables 201 and 202 spaced apart fromeach other, first and second mother substrates 203 and 204 loaded on thefirst and second tables 201 and 202 while covering the space formedtherebetween, first and second cutting wheels 207 and 208 for formingfirst and second scribing lines 205 and 206 on the surfaces of the firstand second mother substrates 203 and 204, and first and second suctionunits 209 and 210 respectively coupled to the first and second cuttingwheels 207 and 208 for sucking in the glass debris generated by thefriction between the first and second cutting wheels 207 and 208 and thefirst and second mother substrates 203 and 204.

[0081] In the apparatus for cutting liquid crystal display panelsaccording to the second embodiment of the present invention, the firstand second mother substrates 203 and 204 are loaded on the first andsecond tables 201 and 202 to be placed across the space formed by thefirst and second tables. Then, the first and second cutting wheels 207and 208 are rolled onto the first and second mother substrates 203 and204 with applying a constant pressure in the space formed between thefirst table 201 and the second table 202, thereby simultaneously formingthe first and second scribing lines 205 and 206 having a groove on thesurfaces of the first and second mother substrates 203 and 204. Thefirst and second suction units 209 and 210 suck in the glass debrisgenerated on the surfaces of the first and second mother substrates 203and 204 by the friction between the first and second cutting wheels 207and 208 and the first and second mother substrates 203 and 204.

[0082] Processes for cutting liquid crystal display panels according tothe second embodiment of the present invention will be explained withreference to FIGS. 7A to 7F.

[0083] First, as shown in FIG. 7A, the attached first and second mothersubstrates 220 and 230 respectively having the thin film transistorarray substrates and the color filter substrates are loaded on the firsttable 231.

[0084] The first mother substrate 220 having the thin film transistorarray substrates is loaded to be stacked on the second mother substrate230 having the color filter substrates. Herein, unlike when the secondmother substrate 230 is stacked on the first mother substrate 220, animpact applied to the thin film transistor array substrates and thecolor filter substrates can be attenuated in the process for cutting thefirst and second mother substrates 220 and 230.

[0085] As shown in FIG. 7B, the first and second mother substrates 220and 230 are positioned on the first and second tables 231 and 232 to beplaced across the space formed therebetween. First and second cuttingwheels 241 and 242 are rolled onto the surfaces of the first and secondmother substrates 220 and 230 with applying a constant pressure at thespace formed between the first and second tables 231 and 232, therebysequentially forming first and second scribing lines 251 and 252 on thesurfaces of the first and second mother substrates 220 and 230. At thispoint, first and second suction units 261 and 262 are coupled to thefirst and second cutting wheels 241 and 242 to suck in the glass debrisgenerated on the surfaces of the first and second mother substrates 220and 230 by the friction between the first and second cutting wheels 241and 242 and the first and second mother substrates 220 and 230.

[0086] As shown in FIG. 7C, a pressure is applied to the first scribingline 251 or the second scribing line 252 through a first roll 211,thereby sequentially cutting the first and second mother substrates 220and 230.

[0087] The first roll 211 simultaneously applies a pressure to a singlepart or a plurality of parts of the first scribing line 251 or thesecond scribing line 252, so that a crack can be propagated on the firstand second mother substrates 220 and 230 along the first and secondscribing lines 251 and 252.

[0088] Additionally, the first roll 211 is coupled to the first cuttingwheel 241 or the second cutting wheel 242 to apply a pressure along thefirst scribing line 251 or the second scribing line 252, therebyapplying the pressure to the first scribing line 251 or the secondscribing line 252 with more efficiency.

[0089] In the meantime, an air curtain 271 is additionally providedabove the space formed between the first table 231 and the second table232. Accordingly, in case that a vertical air current is formed at thespace formed between the first table 231 and the second table 232, thefirst roll 211 applies a pressure to the first scribing line 251 or thesecond scribing line 252, so that glass debris generated by cutting thebonded first and second mother substrates 220 and 230 are prevented frombeing adhered to the first and second tables 231 and 232 or the firstand second mother substrates 220 and 230.

[0090] As shown in FIG. 7D, the cut first and second mother substrates220 and 230 are turned by about 90°.

[0091] As shown in FIG. 7E, the turned first and second mothersubstrates 220 and 230 are positioned on third and fourth tables 233 and234 to be placed across the space formed therebetween. Third and fourthcutting wheels 243 and 244 are bonded to the surfaces of the first andsecond mother substrates 220 and 230 at a constant pressure to berotated at the space formed between the third and fourth tables 233 and234, thereby forming third and fourth scribing lines 253 and 254 on thesurfaces of the first and second mother substrates 220 and 230. At thistime, third and fourth suction units 263 and 264 are connected with thethird and fourth cutting wheels 243 and 244 to suck in the glass debrisgenerated on the surfaces of the first and second mother substrates 220and 230 by a friction between the third and fourth cutting wheels 243and 244 and the first and second mother substrates 220 and 230.

[0092] As shown in FIG. 7F, a pressure is applied to the third scribingline 253 or the fourth scribing line 254 through a second roll 212,thereby sequentially cutting the first and second mother substrates 220and 230.

[0093] The second roll 212, similar to the first roll 211 shown in FIG.7C, simultaneously applies a pressure to a single part or a plurality ofparts of the third scribing line 253 or the fourth scribing line 254, sothat a crack can be propagated on the first and second mother substrates220 and 230 along the third and fourth scribing lines 253 and 254. Also,it is possible that the second roll 212 is connected with the thirdcutting wheel 243 or the fourth cutting wheel 244 to apply a pressurealong the third scribing line 253 or the fourth scribing line 254,thereby applying a pressure to the third scribing line 253 or the fourthscribing line 254 with more efficiency.

[0094] In the meantime, an air curtain 272 is additionally providedabove the space formed between the third table 233 and the fourth table234. Accordingly, in case that a vertical air current is formed at thespace formed between the third table 233 and the fourth table 234, thesecond roll 212 applies a pressure to the third scribing line 253 or thefourth scribing line 254, so that the glass debris generated by cuttingthe bonded first and second mother substrates 220 and 230 are preventedfrom being adhered to the third and fourth tables 233 and 234 or thefirst and second mother substrates 220 and 230.

[0095] The unit liquid crystal display panels cut along the first tofourth scribing lines 251 to 254 are transferred to equipment for alater process by an unloading unit.

[0096] In the apparatus and method for cutting liquid crystal displaypanels according to the second embodiment of the present invention, thefirst and second mother substrates are turned once and the first andsecond mother substrates are scribed twice at the same time, therebyforming the scribing lines. At this time, the glass debris generated onthe surfaces of the mother substrates by the friction between thecutting wheel and the mother substrates are removed by a suction unitcoupled to the cutting wheel, and a pressure is applied to at least onepart of the scribing lines by the roll. Thus, the mother substrates arecut into unit liquid crystal display panels.

[0097] Accordingly, unlike in the first embodiment, in the apparatus andmethod for cutting liquid crystal display panels according to the secondembodiment of the present invention, an apparatus is simplified tominimize the installation cost and the installation space, therebyreducing the time required to cut the unit liquid crystal display panelsand increasing productivity.

[0098] In the meantime, the unit liquid crystal display panels of thethin film transistor array substrate and the color filter substratebonded to each other are formed on the mother substrates with apredetermined interval. Also, a dummy seal pattern for preventing adistortion of the mother substrates is formed at the end portions of thefirst and second mother substrates where the unit liquid crystal displaypanels are not formed.

[0099] In case that the second embodiment of the present invention isapplied to cut the mother substrates where the dummy seal pattern isformed, there is a problem in that the mother substrates may not beeasily separated from the unit liquid crystal display panels.

[0100] Therefore, an apparatus for cutting liquid crystal display panelsaccording to a third embodiment of the present invention is illustratedin FIG. 8, so as to cut the mother substrates where the dummy sealpattern is formed and separated more efficiently.

[0101] As shown in FIG. 8, the apparatus for cutting liquid crystaldisplay panels according to the third embodiment of the presentinvention includes first and second tables 301 and 302 spaced apart fromeach other, first and second suction holes 381 and 382 disposed on thesurfaces of the first and second tables 301 and 302, first and secondmother substrates 303 and 304 loaded on the first and second tables 301and 302 to be placed across the space formed therebetween, first andsecond cutting wheels 307 and 308 for forming first and second scribinglines 305 and 306 on the surfaces of the first and second mothersubstrates 303 and 304, and first and second suction units 309 and 310respectively provided at the first and second cutting wheels 307 and 308for sucking in the glass debris generated by the friction between thefirst and second cutting wheels 307 and 308 and the first and secondmother substrates 303 and 304.

[0102] In the apparatus for cutting liquid crystal display panelsaccording to the third embodiment of the present invention, the firstand second mother substrates 303 and 304 are loaded on the first andsecond tables 301 and 302 in order to be placed across the space formedtherebetween. Then, the first and second cutting wheels 307 and 308 arerolled onto the surfaces of the first and second mother substrates 303and 304 with applying a constant pressure to be rotated in the spaceformed between the first table 301 and the second table 302, therebysimultaneously forming the first and second scribing lines 305 and 306having a groove. The first and second suction units 309 and 310 arecoupled to the first and second cutting wheels 307 and 308, therebysucking the glass debris generated on the surfaces of the first andsecond mother substrates 303 and 304 by the friction between the firstand second cutting wheels 307 and 308 and the first and second mothersubstrates 303 and 304.

[0103] In the meantime, according to the apparatus and method forcutting liquid crystal display panels of the second embodiment of thepresent invention, a pressure is applied to the first scribing line 205or the second scribing line 206 through the first and second rolls 211and 212 in order to cut the first and second mother substrates 203 and204 along the first and second scribing lines 205 and 206 formed on thesurfaces of the first and second mother substrates 203 and 204.

[0104] In the apparatus and method for cutting liquid crystal displaypanels according to the third embodiment of the present invention, thefirst and second suction holes 381 and 382 disposed on the surfaces ofthe first and second tables 301 and 302 are used to hold the first andsecond mother substrates 303 and 304 in cutting them along the first andsecond scribing lines 305 and 306 formed at the surfaces of the firstand second mother substrates 303 and 304.

[0105] More specifically, the first and second mother substrates 303 and304 are held by the first and second suction holes 381 and 382 disposedon the surfaces of the first and second tables 301 and 302. Then, afterforming the first and second scribing lines 305 and 306, the first andsecond tables 301 and 302 each move to a different direction to cut thefirst and second mother substrates 303 and 304 along the first andsecond scribing lines 305 and 306.

[0106] Processes for cutting liquid crystal display panels by applyingthe third embodiment of the present invention will be explained withreference to FIGS. 9A to 9F.

[0107] First, as shown in FIG. 9A, the attached first and second mothersubstrates 320 and 330 respectively having the thin film transistorarray substrates and the color filter substrates are loaded on the firsttable 331.

[0108] The first mother substrate 320 having the thin film transistorarray substrates is loaded to be stacked on the second mother substrate330 having the color filter substrates. Accordingly, an impact appliedto the thin film transistor array substrates or the color filtersubstrates can be more attenuated in the process for cutting the firstand second mother substrates 320 and 330, as compared to when the secondsubstrate 330 is stacked on the first mother substrate 320.

[0109] As shown in FIG. 9B, the first and second mother substrates 320and 330 are positioned on the first and second tables 331 and 332 to beplaced across the space formed therebetween. Then, the first and secondmother substrates are held by the first and second suction holes 381 and382 disposed on the surfaces of the first and second tables 331 and 332.Subsequently, first and second cutting wheels 341 and 342 are rolledonto the surfaces of the first and second mother substrates 320 and 330with applying a constant pressure in the space formed between the firstand second tables 331 and 332, thereby sequentially forming first andsecond scribing lines 351 and 352 at the surfaces of the first andsecond mother substrates 320 and 330. At this time, first and secondsuction units 361 and 362 are coupled to the first and second cuttingwheels 341 and 342 to suck the glass debris generated on the surfaces ofthe first and second mother substrates 320 and 330 by the frictionbetween the first and second cutting wheels 341 and 342 and the firstand second mother substrates 320 and 330.

[0110] As shown in FIG. 9C, the first and second tables 331 and 332loaded the first and second mother substrates 320 and 330 held by thefirst and second suction holes 381 and 382 each moves to the oppositedirections, thereby sequentially cutting the first and second mothersubstrates 320 and 330 along the first and second scribing lines 351 and352.

[0111] The first and second suction holes 381 and 382 suck the air inorder to tightly hold the first and second mother substrates 320 and 330onto the first and second tables 331 and 332. On the other hand, thefirst and second suction holes 381 and 382 inject the air to separatethe first and second mother substrates 320 and 330 from the first andsecond tables 331 and 332, thereby transferring the first and secondmother substrates 320 and 330. Also, the first and second suction holes381 and 382, as shown in FIG. 10A, are formed in the same shape as thesuction unit 380 at the surfaces of the first and second tables 331 and332, thereby sucking the first and second mother substrates 320 and 330more effectively. On the other hand, when a vacuum condition ismaintained at a high state, the first and second suction holes 381 and382 prevent black dot stains from being formed on the first and secondmother substrates 320 and 330.

[0112] In the meantime, an air curtain 371 is additionally providedabove the space formed between the first table 331 and the second table332. Accordingly, in case that a vertical air current is formed at thespace formed between the first table 331 and the second table 332, thefirst and second tables 331 and 332 move to different directions,thereby preventing the glass debris generated by cutting the bondedfirst and second mother substrates 320 and 330 from being adhered to thefirst and second tables 331 and 332 or the first and second mothersubstrates 320 and 330.

[0113] As shown in FIG. 9D, the separated first and second mothersubstrates 320 and 330 are turned by about 90°.

[0114] As shown in FIG. 9E, the turned first and second mothersubstrates 320 and 330 are positioned on third and fourth tables 333 and334 in order to be placed across the space formed therebetween to beheld by third and fourth suction holes 383 and 384 disposed on thesurfaces of the third and fourth tables 333 and 334. Then, third andfourth cutting wheels 343 and 344 are rolled onto the surfaces of thefirst and second mother substrates 320 and 330 with applying a constantpressure in the space formed between the third table 333 and the fourthtable 334, thereby sequentially forming third and fourth scribing lines353 and 354 on the surfaces of the first and second mother substrates320 and 330. At this time, third and fourth suction units 363 and 364are coupled to the third and fourth cutting wheels 343 and 344 to suckin the glass debris generated on the surfaces of the first and secondmother substrates 320 and 330 by the friction between the third andfourth cutting wheels 343 and 344 and the first and second mothersubstrates 320 and 330.

[0115] As shown in FIG. 9F, the third and fourth tables 333 and 334loaded the first and second mother substrates 320 and 330 held by thethird and fourth suction holes 383 and 384 move to the oppositedirections, thereby sequentially cutting the first and second mothersubstrates 320 and 330 and separating from each other along the thirdand fourth scribing lines 353 and 354.

[0116] The third and fourth suction holes 383 and 384, similar to thefirst and second suction holes 381 and 382 of FIG. 9C, suck in the airto tightly hold the first and second mother substrates 320 and 330 ontothe third and fourth tables 333 and 334. On the other hand, the thirdand fourth suction holes 383 and 384 inject the air to separate thefirst and second mother substrates 320 and 330 from the third and fourthtables 333 and 334, thereby transferring the first and second mothersubstrates. Also, the third and fourth suction holes 383 and 384, asshown in FIG. 10B, are formed in the same shape as the suction unit 390at the surfaces of the third and fourth tables 333 and 334, therebysucking in the first and second mother substrates 320 and 330 moreeffectively. Besides, when a vacuum condition is maintained at a highstate, the third and fourth suction holes 383 and 384 prevent black dotstains from being formed on the first and second mother substrates 320and 330.

[0117] In the meantime, an air curtain 372 is additionally providedabove the space formed between the third table 333 and the fourth table334, similar to the air curtain 371 provided above the space formedbetween the first and second tables 331 and 332. Accordingly, in casethat a vertical air current is formed at the space formed between thethird table 333 and the fourth table 334, the third and fourth tables333 and 334 move to the opposite directions, thereby preventing theglass debris generated by cutting the bonded first and second mothersubstrates 320 and 330 from being adhered to the third and fourth tables333 and 334 or the first and second mother substrates 320 and 330.

[0118] The unit liquid crystal display panels, which are cut along thefirst to fourth scribing lines 351 to 354, are transferred to equipmentfor a later process.

[0119] In the apparatus and method for cutting liquid crystal displaypanels according to the third embodiment of the present invention, thefirst and second mother substrates are turned once and the first andsecond mother substrates are scribed twice at the same time, therebyforming the scribing lines. At this time, the glass debris generated onthe surfaces of the mother substrates are removed by the suction unitconnected to the cutting wheel, and the first and second tables or thethird and fourth tables loaded on the mother substrates move to theopposite directions, thereby cutting the mother substrates into unitliquid crystal display panels.

[0120] Accordingly, in the apparatus and method for cutting liquidcrystal display panels according to the third embodiment of the presentinvention, as compared to those of the first embodiment of the presentinvention, the apparatus is simplified to minimize the installation costand the installation space, thereby reducing the processing time takento cut the unit liquid crystal display panels and increasingproductivity.

[0121] Also, in the apparatus for cutting liquid crystal display panelsaccording to the third embodiment of the present invention, the mothersubstrates having the dummy seal pattern can be cut and separated moreefficiently.

[0122] In the meantime, the processes for cutting unit liquid crystaldisplay panels from the mother substrates shown in the second and thirdembodiments of the present invention include a first cutting process forcutting and removing a dummy region where the unit liquid crystaldisplay panels are not formed from the mother substrates, and a secondcutting process for cutting a region where the unit liquid crystaldisplay panels are formed from the mother substrates.

[0123] In the first cutting process, as shown in FIG. 11A, the first andsecond mother substrates 401 and 402 are positioned on the first andsecond tables 403 and 404 so as to be placed across the space formedtherebetween, thereby forming first and second scribing lines 407 and408 by first and second cutting wheels 405 and 406. At this time, firstand second suction units 409 and 410 are coupled to the first and secondcutting wheels 405 and 406 to suck in the glass debris generated on thesurfaces of the first and second mother substrates 401 and 402 by thefriction between the first and second cutting wheels 405 and 406 and thefirst and second mother substrates 401 and 402.

[0124] Similar to the second embodiment of the present invention, apressure is applied to the first scribing line 407 or the secondscribing line 408 through a roll (not shown). Alternatively, similar tothe third embodiment of the present invention, the first and secondtables 403 and 404 having the first and second mother substrates 401 and402 move to the opposite directions, thereby cutting the dummy region430 of a side where the unit liquid crystal display panels are notformed from the first and second mother substrates 401 and 402.

[0125] Then, in the second cutting process, as shown in FIG. 11B, thefirst and second mother substrates 401 and 402, in which the dummyregion 430 is removed by the first cutting process, are positioned onthe first and second tables 403 and 404 to be placed across the spaceformed therebetween, thereby forming third and fourth scribing lines 411and 412 by the first and second cutting wheels 405 and 406. Then,similar to the second embodiment of the present invention, a pressure isapplied to the third scribing line 411 or the fourth scribing line 412through a roll (not shown). Alternatively, similar to the thirdembodiment of the present invention, the first and second tables 403 and404 having the first and second mother substrates 401 and 402 move tothe opposite directions, thereby cutting the unit liquid crystal displaypanels from the first and second mother substrates 401 and 402.

[0126] Subsequently, the first cutting process for cutting the dummyregion 430 from the first and second mother substrates 401 and 402 isperformed, and the second cutting process for cutting the unit liquidcrystal display panels from the first and second mother substrates 401and 402 is repeatedly performed.

[0127] However, when the second embodiment of the present invention isapplied, the dummy region 430 or the unit liquid crystal display panelsmay not be separated from the first and second mother substrates 401 and402 in the first cutting process or in the second cutting process due tothe dummy seal pattern for preventing a distortion formed at the edgeareas of the first and second mother substrates 401 and 402 where theunit liquid crystal display panels are not formed.

[0128] Also, when the third embodiment of the present invention isapplied, in the second cutting process, areas of the unit liquid crystaldisplay panels are wide enough to hold the first and second mothersubstrates 401 and 402 into the first and second tables 403 and 403 andseparate from each other. However, in the first cutting process, sincethe area of the dummy area 430 may be too narrow, the dummy region 430of the first and second mother substrates 401 and 402 cannot be stuckonto the first and second tables 403 and 404.

[0129] An apparatus for cutting liquid crystal display panels accordingto a fourth embodiment of the present invention illustrated in FIG. 12is to solve such problems.

[0130] As shown in FIG. 12, the apparatus for cutting liquid crystaldisplay panels according to the fourth embodiment of the presentinvention includes first and second tables 501 and 502 spaced apart fromeach other, first and second suction holes 581 and 582 disposed on thesurfaces of the first and second tables 501 and 502, first and secondmother substrates 503 and 504 loaded on the first and second tables 501and 502 to be placed across the space formed therebetween, first andsecond cutting wheels 507 and 508 for forming first and second scribinglines 505 and 506 at the surfaces of the first and second mothersubstrates 503 and 504, first and second suction units 509 and 510respectively provided at the first and second cutting wheels 507 and 508for sucking in the glass debris generated by the friction between thefirst and second cutting wheels 507 and 508 and the first and secondmother substrates 503 and 504, and a robot grip 540 provided at thespace formed between the first and second tables 501 and 502 forremoving the dummy region 530 of the first and second mother substrates503 and 504 along the first and second scribing lines 505 and 506.

[0131] In the apparatus for cutting liquid crystal display panelsaccording to the fourth embodiment of the present invention, the firstand second mother substrates 503 and 504 are loaded on the first andsecond tables 501 and 502 to be placed across the space formedtherebetween. Then, the first and second cutting wheels 507 and 508 arerolled onto the surfaces of the first and second mother substrates 503and 504 at the space formed between the first table 501 and the secondtable 502, thereby simultaneously forming the first and second scribinglines 505 and 506 having a groove. The first and second suction units509 and 510 are coupled to the first and second cutting wheels 507 and508 to suck in the glass debris generated on the surfaces of the firstand second mother substrates 503 and 504.

[0132] In the meantime, according to the apparatus and method forcutting liquid crystal display panels according to the third embodimentof the present invention, the first and second mother substrates 303 and304 are held by the first and second suction holes 381 and 382 disposedon the surfaces of the first and second tables 301 and 302. Then,forming the first and second scribing lines 305 and 306, the first andsecond tables 301 and 302 move to the opposite directions, therebycutting the first and second mother substrates 303 and 304 along thefirst and second scribing lines 305 and 306.

[0133] However, as explained with reference to FIGS. 11A and 11B, sincethe area of the dummy region 430 may be too narrow, the dummy region 430of the first and second mother substrates 401 and 402 cannot be stuck onthe first and second tables 403 and 404.

[0134] In the meantime, according to the apparatus and method forcutting liquid crystal display panels according to the fourth embodimentof the present invention, as shown in FIG. 12, the robot grip 540 isprovided at the space formed between the first table 501 and the secondtable 502, thereby selectively separating the dummy region 530 from thefirst and second mother substrates 503 and 504.

[0135] In order to easily separate the dummy region 530 from the firstand second mother substrates 503 and 504 by the robot grip 540, thefirst and second scribing lines 505 and 506 are formed by the first andsecond cutting wheels 507 and 508, and then a pressure is applied to thefirst scribing line 505 or the second scribing line 506 by a roll topropagate a crack, as shown in the second embodiment.

[0136] The liquid crystal display panel may have a different sizeaccording to a model. Therefore, it is desirable to control the width ofthe robot grip 540 by using a sub motor and etc.

[0137] Also, in case that the first mother substrate 503 having the thinfilm transistor array substrates is stacked on the second mothersubstrate 504 having the color filter substrates, the thin filmtransistor substrates are protruded from the color filter substrates.Accordingly, the robot grip 540 is constructed to hold the dummy region530 at a location lower than the first and second mother substrates 503and 504. On the other hand, the robot grip 540 has to grip the dummyregion 530 at a location higher than the first and second mothersubstrates 503 and 504 to prevent an impact applied to the unit liquidcrystal display panels in advance. To this end, the robot grip 540 maybe fabricated to control the height thereof by using a servomotor.

[0138] In the meantime, when the robot grip 540 separates the dummyregion 530 selectively from the first and second mother substrates 503and 504 at the space formed between the first table 501 and the secondtable 502, the glass debris may be generated and adhered to the surfaceof the second table 502.

[0139] In case that the glass debris are adhered to the surface of thesecond table 502, a scratch or stain may appear on the surface of thefirst mother substrate 503 when the cut liquid crystal display panelsare loaded on the second table 502.

[0140] Accordingly, a cover 541 is additionally coupled to the robotgrip 540 to prevent the glass debris from being adhered to the secondtable 502.

[0141] The cover 541 can be attached to the robot grip 540 by anadhesion method, or can be mounted thereon and detached therefrom by apin insertion method. Also, the cover 541 can prevent a damage caused bycollisions with other components by using a urethane or vinyl material.Also, the cover 541 may be formed to be divided into two parts withrespect to the middle location of the robot grip 540 having a separationmargin so that a width of the robot grip 540 can be varied according toa size of the liquid crystal display panel.

[0142] In the meantime, the cover 541 is attached to the robot grip 540and a vertical air current is additionally formed at the space formedbetween the first table 501 and the second table 502 by providing an aircurtain 550 above the space formed between the first table 501 and thesecond table 502, so that the glass debris, generated when the robotgrip 540 separates the dummy region 530 selectively from the first andsecond mother substrates 503 and 504 at the space formed between thefirst table 501 and the second table 502, is effectively prevented frombeing adhered to the surface of the second table 502.

[0143] As aforementioned, in the apparatus for cutting liquid crystaldisplay panels according to the present invention, the glass debrisgenerated in the process for cutting the large mother substrates intothe unit liquid crystal display panels can be prevented from beingadhered to the surface of the mother substrate or the table on which themother substrate is loaded.

[0144] Accordingly, a scratch or stain is prevented from being formed onthe surface of the liquid crystal display panel, thereby increasing apicture quality of the liquid crystal display panel, reducing thedefects of a product, and thus improving productivity.

[0145] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the apparatus for cuttingthe liquid crystal display panel of the present invention withoutdeparting from the spirit or scope of the inventions. Thus, it isintended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. An apparatus for cutting liquid crystal displaypanels, comprising: at least one table receiving bonded mothersubstrates having a plurality of unit liquid crystal display panels; atleast one cutting wheel forming a scribing line on a surface of thebonded mother substrates; and a suction unit coupled to the at least onecutting wheel and sucking in glass debris on the surface of the bondedmother substrates.
 2. The apparatus of claim 1, wherein the bondedmother substrates include a first mother substrate having a plurality ofcolor filter substrates, and a second mother substrate having aplurality of thin film transistor substrates.
 3. The apparatus of claim1, wherein the suction unit is synchronized with a motion of the cuttingwheel.
 4. The apparatus of claim 1, further comprising at least one rollapplying a pressure onto at least a part of the scribing line.
 5. Theapparatus of claim 4, wherein the roll is synchronized with a motion ofthe cutting wheel.
 6. The apparatus of claim 1, wherein the at least onetable includes a first table and a second table, and the bonded mothersubstrates are loaded on the first and second tables to be placed acrossa space formed between the first and second tables.
 7. The apparatus ofclaim 6, further comprising an air curtain above the space between thefirst table and the second table.
 8. The apparatus of claim 1, whereinthe at least one table has at least one suction hole to hold the bondedmother substrates.
 9. The apparatus of claim 8, wherein the suction holehas a dot shape or a stripe shape.
 10. The apparatus of claim 6, whereinthe first and second tables move away from each other.
 11. The apparatusof claim 6, further comprising a robot grip provided at the space formedbetween the first table and the second table for removing a dummy regionfrom the bonded mother substrates.
 12. The apparatus of claim 11,further comprising a cover bonded to the robot grip.
 13. The apparatusof claim 12, wherein the cover is formed of one of urethane and vinyl.